from sys import stdin
from math import sqrt

x1, y1, x2, y2 = [float(x) for x in stdin.readline().rstrip().split()]
print(sqrt((x2-x1)**2 + (y2-y1)**2)) from sys import stdin from math import sqrt float(x) for x in stdin.readline().rstrip().split() for x in stdin.readline().rstrip().split() x stdin.readline().rstrip().split() stdin.readline().rstrip().split stdin.readline().rstrip() stdin.readline().rstrip stdin.readline() stdin.readline stdin readline rstrip split for x in stdin.readline().rstrip().split() float(x) float x x1, y1, x2, y2 = [float(x) for x in stdin.readline().rstrip().split()] x1 [float(x) for x in stdin.readline().rstrip().split()] y1 x2 y2 print(sqrt((x2-x1)**2 + (y2-y1)**2)) print sqrt((x2-x1)**2 + (y2-y1)**2) sqrt (x2-x1)**2 + (y2-y1)**2 (x2-x1)**2 x2-x1 x2 x1 2 (y2-y1)**2 y2-y1 y2 y1 2 y1, x2, y2 = [float(x) for x in stdin.readline().rstrip().split()] [float(x) for x in stdin.readline().rstrip().split()] y1 x2, y2 = [float(x) for x in stdin.readline().rstrip().split()] [float(x) for x in stdin.readline().rstrip().split()] x2 x1, y1, x2, y2 = [float(x) for x in stdin.readline().rstrip().split()] [float(x) for x in stdin.readline().rstrip().split()] x1 y2 = [float(x) for x in stdin.readline().rstrip().split()] [float(x) for x in stdin.readline().rstrip().split()] y2
from sys import stdin
from math import sqrt

x1, y1, x2, y2 = [float(x) for x in stdin.readline().rstrip().split()]
print(sqrt((x2-x1)**2 + (y2-y1)**2))
